Answer:
B) lichens
Explanation:
The pioneer species refers to the first few species which can colonize the barren or disturbed area. The succession process can be defined into two types: the primary and secondary succession.
In the primary succession, the terrestrial succession takes place when the pioneer species grow on the bare rock. The pioneer species which grows on the bare rock are the "lichens" which produce certain acidic compounds which can weather the rocks and helps in the formation of the soil and increasing the nutrient level.
Thus, Lichens is the correct answer.